An automotive engineer's testimony concerning the moments before a fatal head-on crash on Highway 17 two years ago was called into question in court Monday at the impaired driving trial of Pembroke dentist Christy Natsis.

Evidence revealed earlier in the trial showed Casey was impaired at the time of the crash. Also in the trial, blood alcohol evidence showing Natsis was impaired was ruled inadmissible.

Now the Crown’s case relies on evidence showing the damage to her car and on information from the power control module of Natsis's Ford Expedition, which acts as a type of black box for the vehicle.

Ford automotive engineer Jim Engle testified that none of the data from the power control module in the key moments before impact was lost. (CBC)

The court had earlier heard from Jim Engle, an automotive engineer with the Ford Motor Company and an expert witness in more than 20 trials.

Delay in reviewing data, court hears

Engle had testified the recorder did not show any indication Natsis touched her brake in the seconds leading up to the collision, said Engle. It also showed Natsis was travelling at about 88 km/h at the moment of impact, he said.

Defence lawyer Vincent Clifford tried to cast doubt on the reliability of Engle's evidence, questioning why the module sat on the engineer's desk for over a year before the data was analyzed.

Engle said it took that long because an outside agency had to design software to download the data.

Clifford asked Engle if anyone had peer reviewed his analysis of the data.

"I had the best and most knowledge" on this issue, said Engle.

30 seconds of data erased in error

The power train control module typically records about 95 seconds before a crash and about five seconds afterwards. But in this case, there were two failures. The machine failed to flag the moment her vehicle's airbags deployed and about 30 seconds of data was later overwritten by error, the court had earlier heard.

This photographic evidence shows the aftermath of the fatal crash along Highway 17 west of Ottawa.

But the errors did not compromise the information during the crucial period before the impact, said Engle.

Earlier in the trial, video showed a black Ford Explorer backing out of a Kanata bar and crashing into a parked car before driving away.

The Crown is expected to rely heavily on the photo evidence to get a conviction on the charge of “dangerous driving causing death."

Justice Neil Kozloff delayed the trial due to his and the lawyers’ schedules conflicting. The trial began almost one year ago.